1. Field of the Invention
The technical scope of the invention is that of folding devices for vehicle windscreens.
2. Description of the Related Art
For reasons of transport convenience, certain vehicles need to be able to lower all or part of their windscreen. This enables a lesser volume to be obtained, or for example, enables auxiliary equipment to be passed through without interfering with the windscreen.
This is the case in particular for artillery mounted on carrier trucks and for which during air transport phases the gun barrel needs to be lowered into a substantially horizontal position causing the gun barrel to pass through the cab which is only possible if the windscreen is folded down.
This type of lowering device is also well known on vehicles such as the well-known Jeep or others described by patent GB592272. On this type of device, the glass part of the windscreen is integral with a frame or with uprights that are hinged with respect to the vehicle's structure thanks to a horizontal pivot link that is located below the lower edge of the glass part. This pivot link enables the windscreen to be lowered onto the hood of the vehicle by simple rotation of the glass part.
However, on certain vehicles, and namely on military armored vehicles, the windscreen incorporates very thick armored glass. This thickness does not enable the positioning of a hinge on its lower edge to enable the windscreen to fold down since the over-thickness of the windscreen would interfere with the vehicle hood.
Furthermore, it is sometimes impossible for reasons of its integration into the vehicle to position a rotational axis for the windscreen below the latter.
By way of example, FIG. 1 shows a configuration to mount a windscreen 4 onto a vehicle 1 whose structure incorporates a cab 2 with a front hood 3. This windscreen 4 incorporates an armored glass part 4a that is relatively thick and integral with a frame 5.
Note that, in this configuration, the lower edge 5a of the frame is very close to the front hood 3. It is not possible to place a hinge below this lower edge 5a. 
If, on the contrary, a rotational pivot 6 is positioned integral with the cab structure and above the lower edge 5a, it is clear that the windscreen 4 cannot be folded down around this pivot 6 since the lower edge 5a will mechanically interfere with the cab.